Dental mold-cup



C. A. PALMER.

DENTAL MOLD CUP.

APPLICATION FILED NOV. 26, I919.

1, 35 1 584, Patented Aug. 31, 1920.

INVENTOR 1 CfiaI/fs A. Pa/nrer ATTORNEY tion to retain the pattern UNITESTATES TT- Oi FEQE.

DENTAL MOLD-CUP.

Application filed November 26, 1919.

To all whom it may oncern lie. it known that I. (linniLns A. Paniunn acitizen ot the United States, residii'igat Heattle. in the count of Kingand State of Washington. have invented certain new and usefulimprovements in Dental iiiolil-'-.nps. of which the following is aspecification.

This invention relates to detail mold cups; and its object is theimprovement ot mold cups whereby the manufacture of tooth-inlays isfacilitated.

The invention consists in a substantially cylindrical cup havingcavities in its opposite ends which are connected by an axially disposedopening. The invention further consists in. producing a cup of thischaracter from a moisture absorbent material.

In the accompanying drawings. Figure l is a side elevational view andFig. 2 is an end view of a mold cup embodying the present invention.Figs. 3, 4 and 5 are longitudinal sectional views of the same toillustrate the application of the invention.

In carrying out my invention I )rovide a cup A of a cylindrical form,pre erabl'y, made of a porous material having water absorbingcharacteristics.

in its opposite ends the cup is provided with conoidal cavities B and Cwhich are communicatively connected by a relatively small hole I)disposed axially of the cup.

In using the cup, a pattern E of wax or the like taken of a tooth cavityis first given a thin coating of clayey substance conventionally knownas investment, and is impaled upon a wire sprue F of a diameter to fitwithin the hole D in which the sprue is inserted and thereby held inupright posiin proximity of the center of the cavity B, as shown in Fig.3.

The pattern is next embedded in a plastic investment G, Fig. *i. whichis quickly dried by having the water extracted therefrom by beingabsorbed by the material of the containing cup.

The cup is then exposed to the action of a blowpipe flame, or anequivalent. to cause the moisture to be evaporated from the cup.complete the hardening of the investment and raise the temperature ofthe latter suiti- Specification of Letters Patent.

Patented Aug. 31, 1920.

Serial No. 340.393.

ciently to effect the destruction oi the wax pattern.

The cup is then inverted into its Fin". Ft position the spruc i removedfrom the cup and a piece of metal ii. such. for example. as a goldnugget is placed in the cavity t. The flame is again applied to renderthe cup hot and effect the melting of the metal which is caused to Howor he forced through the hole 1) t till the mold formed by the patternI) in the investment G.

The forcing of the molten metal through the cup hoie may be accomplishedby any well known suitable means.

The cup and investment are. then broken a way to release the casting orinlay from the mold.

in the practice oi my invention, best rc- Hllll'f-l are obtained withwhat may be termed absorbent investments from which the uiois ture maybe readily withdrawn by being absorbed by the cup and hardens when heatis applied to the latter rather than that type of investments whichcrystallizes in setting.

The invention is of inexpensive construction. convenient to use. andetlicient in producing: a high quality of Work.

What l claim. is-

i. dental mold-cup consisting of :1 cylindrical body made of porousmaterial havingr water absorbent characteristics. said cup belie:provided in each end with a conoidal cavity which cavities areconinutniratir ly connect d by a sin: hole wherein a spine wire can besupported by the cup struetuie in a combination. a dental molilecupconsisting" of a body having, cavities at its opposite ends connected byaxially disposed hole. a sprue wire adapted to lit within said hole andthereby be retained in position to extend into both of the cavities, andan in vestinent for producing a mold about a. pattern impaled upon saidwire in one of said cavities.

Signed at tiattle. Washington. this lTth day of November 1919.

CH A RLE S A P A LM E R.

